The present invention relates to small interfering ribonucleic acids (hereinafter referred to as siRNAs). siRNAs are small double stranded RNA, usually 20 to 25 nucleotides in length which bind to other nucleic acids and interfere with or silence expression events. siRNAs are used to study expression and disease states involving expression events. siRNAs have utility controlling of expression at the cellular level to treat disease. However, siRNA have been limited by difficulty in placing the RNA in the cell or cells.
It is difficult to make liposomes of a size that permits absorbtion or other delivery of siRNAs to the interior of cells. Liposomes having a diameter measured in nanometers, from about 10 to 500 nanometers, are referred to as nanosomes. Nanosomes have potential as a delivery vehicle for siRNAs. However, it is difficult to make nanosomes with consistent and high load of an agent such as siRNAs. Processes for loading an agent do not necessarily permit the recycling of agent not incorporated into the liposome resulting in a loss of the agent and higher costs of manufacture.